Atrial Septal Defect Closure for Right-to-Left Shunting Following a MitraClip Repair

Abstract: Percutaneous repair of the mitral valve has been widely adopted for the treatment of primary, symptomatic severe mitral regurgitation in patients at prohibitive risk for surgical intervention. We present a case of an elderly female patient with moderate-to-severe mitral regurgitation who underwent MitraClip procedure, with postprocedural course remarkable for the development of right-to-left shunting and hypoxia, for which the patient underwent a percutaneous repair of the atrial septal defect with immediate recovery of oxygen saturation.

J INVASIVE CARDIOL 2016;28(9):E80-E81

Key words: mitral valve repair, MitraClip device

Case Presentation

Percutaneous repair of the mitral valve, using an edge-to-edge leaflet MitraClip device (Abbott Vascular), is a minimally invasive technique that is approved by the United States Food and Drug Administration for the treatment of primary, symptomatic, moderate-to-severe mitral regurgitation in patients with favorable anatomy who are at prohibitive risk for surgical intervention.¹ Percutaneous repair of the mitral valve has shown equivalent prevalence of moderate-to-severe and severe mitral regurgitation or mortality at 4 years compared with surgical repair.² As a result, these observations have led to widespread adoption of this novel technique.  

An 86-year-old female with history of coronary artery disease and a previously placed right coronary artery stent, atrial fibrillation on apixaban, normal left and right ventricular function with moderate-to-severe primary mitral regurgitation, and recurrent hospitalizations for heart failure was deemed a high-risk surgical candidate and underwent percutaneous repair of the mitral valve. Preoperative transesophageal echocardiography (TEE) revealed thickened mitral valve leaflets with normal opening and bileaflet prolapse (Figure 1A). Echocardiography also revealed severe tricuspid regurgitation with tethering of the leaflets due to tricuspid annular dilation and a severely dilated right atrium (Figure 1B). Intraoperatively, venous access was obtained and a 22 Fr sheath was advanced into the left atrium after TEE-guided transseptal puncture. Left atrial pressure was measured at 15 mm Hg (v-waves to 20 mm Hg) and right atrial pressure was 18 mm Hg (v-waves to 24 mm Hg). Using TEE and fluoroscopic guidance, two clips were placed after confirmation of satisfactory position; TEE showed a reduction of the mitral regurgitation to mild with no transmitral gradient (Figure 2A). 

Once the 22 Fr guiding sheath was removed, a significant right-to-left shunt developed (Figure 2B), with the patient’s oxygen saturation acutely dropping from 100% to 89% on high-flow oxygen. Therefore, the atrial septal defect was closed with an 8 mm Amplatzer atrial septal occluder device (St. Jude Medical) with oxygen saturation recovering to 98%. Postoperatively, the patient had an uncomplicated course and was discharged in stable condition.

Percutaneous repair of the mitral valve using the MitraClip device has been widely adopted as an option for high-risk surgical patients with suitable anatomy. It utilizes a transseptal route with the creation of an atrial septal defect after withdrawal of the guiding sheath. This has been shown to have positive and negative hemodynamic and clinical effects, with immediate hemodynamic relief of the left atrium due to left-to-right shunting,³ but worse mortality outcomes in the long term.⁴ We present the case of a patient with moderate-to-severe mitral regurgitation who underwent MitraClip procedure, with immediate postprocedural course remarkable for the development of hypoxia due to right-to-left shunting, for which the patient underwent percutaneous repair of the atrial septal defect with immediate recovery of oxygen saturation.

References

1.    Abbott Vascular. Abbott’s first-in-class MitraClip device now available for US patients (press release). https://abbott.mediaroom.com/2013-10-25-Abbotts-First-In-Class-MitraClip-Device-Now-Available-for-U-S-Patients. Published October 25, 2013. Accessed April 5th 2016.

2.    Mauri L, Foster E, Glower DD, et al. 4-year results of a randomized controlled trial of percutaneous repair versus surgery for mitral regurgitation. J Am Coll Cardiol. 2013;62:317-328.

3.    Hoffmann R, Altiok E, Reith S, Brehmer K, Almalla M. Functional effect of new atrial septal defect after percutaneous mitral valve repair using the MitraClip device. Am J Cardiol. 2014;113:1228-1233.

4.    Schueler R, Öztürk C, Wedekind JA, et al. Persistence of iatrogenic atrial septal defect after interventional mitral valve repair with the MitraClip system: a note of caution. JACC Cardiovasc Interv. 2015;8:450-459.

From the Division of Cardiology, Department of Medicine, New York Presbyterian Hospital – Weill Cornell Medical Center, New York, New York.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript submitted May 5, 2016 and accepted May 15, 2016.

Address for correspondence: S. Chiu Wong, MD, Professor of Medicine, Greenberg Cardiology Division, Director, Cardiac Catheterization Laboratory, Weill Medical College of Cornell University, 525 East 68th Street, Starr-4, New York, NY 10021. Email: scwong@med.cornell.edu